1. Field of the Invention
The present invention relates to an imaging apparatus, more specifically, to an enhancement in sensitivity and a reduction in power consumption of an imaging apparatus such as a digital camera or the like.
2. Description of the Prior Art
In recent years, a CCD has been used mostly for an image pick-up device used in an imaging apparatus of a digital camera and the like. However, sensitivity is generally insufficient in the CCD. For example, there is a case that a sufficient luminance cannot be obtained with 1/30 seconds of an exposure on a dark object even though it may be recognized fully by a human.
To solve such a case, it is known that an extension of a storage time of the CCD is an effective measure.
However, it is difficult to take beautiful photographs due to blurring caused by shaking or an influence by a movement of an object even if the sufficient luminance is obtained by extending and setting the storage time to 1 second.
Also, if a limitation is set to the storage time to avoid influences such as the blurring by the shaking, there is a problem that S/N of the photographs becomes poor, since a gain has to be applied by a processing device like AGC (Automatic Gain Control).